<p>给你一个二维 boolean 矩阵&nbsp;<code>grid</code>&nbsp;。</p>

<p>如果&nbsp;<code>grid</code> 的 3 个元素的集合中，一个元素与另一个元素在 <strong>同一行</strong>，并且与第三个元素在 <strong>同一列</strong>，则该集合是一个 <strong>直角三角形</strong>。3 个元素 <strong>不必</strong> 彼此相邻。</p>

<p>请你返回使用 <code>grid</code>&nbsp;中的 3 个元素可以构建的 <strong>直角三角形</strong> 数目，且满足 3 个元素值 <strong>都</strong>&nbsp;为 1 。</p>

<p>&nbsp;</p>

<p><strong class="example">示例 1：</strong></p>

<div style="display:flex; gap: 12px;">
<table border="1" cellspacing="3" style="border-collapse: separate; text-align: center;">
	<tbody>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
	</tbody>
</table>

<table border="1" cellspacing="3" style="border-collapse: separate; text-align: center;">
	<tbody>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
	</tbody>
</table>
</div>

<div class="example-block">
<p><span class="example-io"><b>输入：</b>grid = [[0,1,0],[0,1,1],[0,1,0]]</span></p>

<p><span class="example-io"><b>输出：</b>2</span></p>

<p><b>解释：</b></p>

<p>有 2 个值为 1 的直角三角形。注意蓝色的那个 <strong>没有&nbsp;</strong>组成直角三角形，因为 3 个元素在同一列。</p>
</div>

<p><strong class="example">示例 2：</strong></p>

<div style="display:flex; gap: 12px;">
<table border="1" cellspacing="3" style="border-collapse: separate; text-align: center;">
	<tbody>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
	</tbody>
</table>
</div>

<div class="example-block">
<p><span class="example-io"><b>输入：</b>grid = [[1,0,0,0],[0,1,0,1],[1,0,0,0]]</span></p>

<p><span class="example-io"><b>输出：</b>0</span></p>

<p><strong>解释：</strong></p>

<p>没有值为 1 的直角三角形。注意蓝色的那个&nbsp;<strong>没有</strong> 组成直角三角形。</p>
</div>

<p><strong class="example">示例 3：</strong></p>

<div style="display:flex; gap: 12px;">
<table border="1" cellspacing="3" style="border-collapse: separate; text-align: center;">
	<tbody>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
	</tbody>
</table>

<table border="1" cellspacing="3" style="border-collapse: separate; text-align: center;">
	<tbody>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
		<tr>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid red; --darkreader-inline-border-top: #b30000; --darkreader-inline-border-right: #b30000; --darkreader-inline-border-bottom: #b30000; --darkreader-inline-border-left: #b30000;">1</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
			<td data-darkreader-inline-border-bottom="" data-darkreader-inline-border-left="" data-darkreader-inline-border-right="" data-darkreader-inline-border-top="" style="padding: 5px 10px; border: 1px solid black; --darkreader-inline-border-top: #8c8273; --darkreader-inline-border-right: #8c8273; --darkreader-inline-border-bottom: #8c8273; --darkreader-inline-border-left: #8c8273;">0</td>
		</tr>
	</tbody>
</table>
</div>

<div class="example-block">
<p><span class="example-io"><b>输入：</b>grid = [[1,0,1],[1,0,0],[1,0,0]]</span></p>

<p><strong>输出：</strong>2</p>

<p><strong>解释：</strong></p>

<p>有两个值为 1 的直角三角形。</p>
</div>

<p>&nbsp;</p>

<p><strong>提示：</strong></p>

<ul>
	<li><code>1 &lt;= grid.length &lt;= 1000</code></li>
	<li><code>1 &lt;= grid[i].length &lt;= 1000</code></li>
	<li><code>0 &lt;= grid[i][j] &lt;= 1</code></li>
</ul>
